Thomas j



(No Model.) T. J. BARRON.

LEVELING INSTRUMENT. N0- .604. 7 Egxtented Dec. 1, 1885.

N. PETERS. Phuln-Lilhogriphun Washington, D, (L

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TAT-ES THOMAS J. BARRON, OF NEVNAN, GEORGIA.

LEVELING -ENSTRU M ENT.

SPECIFICATION forming part of Letters Patent No. 331,604, dated December 1, 1885.

Application filed May 4, 1885. Serial No. 164,343. (No model.)

.To all whom it may concern:

Be it known that I, THOMAS J. BARRON, of Newnan, in the State of Georgia, have invented certain new and useful Improvements in Leveling-Instruments; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it pertains to make and use it, reference being had to the accompanying drawings,- which form part of this specification.

My invention relates to an improvement in leveling-instruments; and it consists in, first, the combination of the tripod, the staff which is vertically adjustable thereon, and which is provided at its upper end with aball-bearing, with the table or hearing which is applied thereto, and which has a socket in its under side to receive the ball and revolve freely thereon; second, the combination of the tripod, the staff, the table or frame which is journaled upon its top, and which has a socket in its under side to receive the ball'bearing of the staff, and a socket on its upper side in which the sighting-tube and level are placed and loosely held in such a manner that they can be revolved freely around; third, the combination of the tripod, the staff, the table or frame carrying the sighting-tube upon its top, the vertical rods or braces, the circular frame, which is secured to theirlower ends, and which serves as a counter balance, and a bridge which extends across the top of the frame, and through which the set-screws are passed for the purpose of adjusting the table or frame upon the top of the staff, all of which willbe more fully described hereinafter.

Figure 1 represents aside elevation of alevelinginstrument embodying my invention, partly in sections. Fig. 2 is a horizontal section of the same, looking down upon thebalancing-frame. Fig. 3 shows another form or frame or sighting devices. Fig.4 is a plan view of the table alone. Fig. 5 is a vertical cross-section taken through the table alone and at right angles to Fig. 1.

A represents the tripod, which may either be of the construction here shown or any other that may be preferred. Passing through the socket upon the top of this tripod is the staff B, which is held in any desired relation by means of the setscrew G, which passes through the side of the socket and bears against the side of the rod. This rod B is preferably made hollow for the sake of lightness, and secured in its upper end by means of the clamping-screw E is a vertical adjustable rod, F, which has a ball-bearing, G. formed upon its upper end. This rod F is made vertically adjustable upon the staff for the purpose of raising and lowering theframe or table which carries the sighting-tube, without the necessity of making the adjustment upon the top of the tripod. By having a bearing, G, as shown, the frame carrying the sighting-tube upon its top readily adjusts itself to a level as soon as it is left free to move.

The table or frame H is preferably made round, and has ears or projections I formed on opposite sides, as shown. side of this table or frame is formed asocket, J, in which the bearingG fits. In the top of the table or frame is made a large circular socket, in which the bearing or pivot B for the sightingtube and level is placed. Extending through the ears or projections formed upon opposite sides of the table or frame are the Vertical rods L, which have their lower ends passed through the circular frame and counter-weight N. The holes or openings which are made through this frame N are made larger than are necessary simply to allow the ends of the rods to pass through, and one of them is made in the form of a slot, so as to allow the frame to be adjusted upon the rodsin case one side should happen to be heavier than the other. By means of this adjustment the frame can be attached to the rods so that it will always swing freely to a center and exactly balance the frame or table and the sighting-tube placed thereon. Were it not for this adj ustment, when this frame was left free to vibrate, it would not bring the bubble to the center of the level if the frame were heavier on one side than on the other. Extending across the top of this circular frame or counterbalance N is the bridge 0, which is arched at its center, so as to raise it slightly upward, and which has an opening through each end, so as to allow the vertical rods to pass through and center it in position between the rods of the frame. At the center of this bridge is formed a ring or In the under between the top and bottom of the rod B.

collar, Q, through which are passed the four set-screws B. These screws, by hearing against the side of the staff, adjust the frame or table into any desired position. When the instrument is first set up, these set-screws are slackened, and then the counter-weight N causes the table to at once adjust itself intoahorizontal position. As soon as the bubble of the level shows that the table is in a horizontal position the screws are tightened against the staff, so as to hold it rigidly in place.

The bearing or pivot It of the frame upon which the sighting'tube and level are placed is made circular, so as to fit in the circular socket in the top of the table, and is grooved upon its edge, so that the set-screws which pass through the side of the table will catch in the groove, and, while they prevent the pivot or bearing from being removed from its socket, allowit to revolve freely around therein, so as to move the sighting-tube in any direction. The level may be placedjust over the pivot, as shown, where a sighting-tube is used; or, if simply sights are used insteadof a tube, it may be placed upon the top of the frame. The bridge is here shown above the top of the frame N; but it may be placed below the frame, or it may be used at any point If this bridge is to be attached to the rods L and made verticlly adjustable, two set-screws will have to be used for the purpose of adjusting the bridge up and down.

Having thus described my invention, I claim- 1. The combination of the tripod, the stafi which is secured thereto, and which has a separate bearing-point attached to its upper end, with the table having a socket in itstop to receive a pivot upon which the sighting-tube is 0 placed, and a socket in its under side, and a counter-balance connected to it by means of suitable rods, substantially as shown.

2. The combination of the table. having a socket or bearing in its under side, a circular 5 socket in its top, with the frame upon which the sighting-tube and level are placed, and which frame has a circular grooved pivot which catches in the socket, and the set-screws which are passed through the side of the ta- 53 ble, so as to catch in the groove on the side of the pivot, substantially as shown.

3. The combination of the table or frame upon which the sighting-tube and the level are placed, with a counter-weight which is 55 connected to the table at a suitable distance below it, the staff upon which the tableissupported, a bridge which is connected to the counterweight, and setscrews which are passed through the bridge for securing the ta- 6o ble in any desired position, substantially as described.

4:. The combination, in a leveling-instrument, of a frame upon which the sightingtube and level are placed, with the bridge and 6 5 a counter-Weight which is suspended from the table, and which is connected thereto by suitable rcds, the counter-weight and bridge having a slot or slots through them for their adj nstment upon the rods, substantially as speci- 7o fied.

In testimony whereofI affix my signature in presence of two witnesses.

THOMAS J. BARRON.

Witnesses:

M. B. PIERSON, W. A. MITOHELL. 

